import numpy as np

arr1 = np.array([1, 2, 3])
print('一维数组arr1:  \n', arr1)
arr2 = np.array((4.5, 5.6, 6.8), dtype='int32')
print('一维数组arr2: \n', arr2)
arr3 = np.array([[1, 2, 3], [4, 5, 6]], dtype='float32')
print('2*3的二维数组arr3: \n', arr3)

arr11 = np.array([1.1, 2.2, 3.3])
print('一维数组arr11: \n', arr11)
arr111 = np.array([-1, -2, -3])
print('一维数组arr111: \n', arr111)
arr1111 = np.array([3., -2, 2.3])
print('一维数组arr111: \n', arr1111)
